It is known, in particular via the patent document EP-1-092-347 entitled “Method of Automatic Sexing of Chicks,” to determine the sex of chicks based on an examination of the cartilage of the feathers at the upper ends of the wings. In a first step of this method, the chick is conveyed in such a way that it loses its balance and that it automatically spreads out its wings via reflex. Photographs are taken of the spread wings, and the photographs are then analysed in order to deduce the sex of the chicks, with the chicks then being sorted according to sex. The '347 patent proposes several conveying devices making it possible to obtain this loss of balance of the chicks. In one of the proposed embodiments, the chicks are initially placed in the center of a carrousel, where they slide in the channels of the carrousel and fall into funnels that rest on the buckets of a bucket conveyor. The feet of each chick rest on the bottom of the bucket, and the bucket is descended downwards in relation to the funnel in such a way that the chick loses its balance and falls again with the wings spread out in the bucket, with its wings remaining spread out on an upper horizontal lip of the bucket. When the bucket descends, the chick is supported solely by its wings against the funnel and must fold its wings further upwards in order to fall back into the bucket, which can cause certain injuries to wings. Furthermore the chick can remain blocked in the funnel, with its wings pressing against the inclined wall of the funnel.
The '347 patent also proposes conveying devices, of the endless conveyor type, wherein the chicks are arranged one after one another, with the automatic spreading of the wings being obtained by vibration, oscillation or electrical discharge. However, these devices do not make it possible to guarantee exact spacing pitch between the chicks, which is needed for taking photographs.